Preparation method of multi-profile bulletproof shell

Abstract

The invention provides a preparation method of a multi-profile bulletproof shell, which comprises the following steps: cutting a flat plate prepared in advance to obtain profile blocks and long strips, and then splicing and combining on a single male die. The mold is low in cost; each molded surface of the special-shaped bulletproof shell can be ensured to have the same thickness and bulletproof performance; and special-shaped shells with various thicknesses can be formed according to requirements by utilizing one male mold, the quality of formed products is high, the protection performance is good, and batch production can be realized.

Description

Technical Field

[0001] The invention belongs to the technical field of bulletproof armor, and in particular relates to a method for preparing a multi-surface bulletproof shell. Background Art

[0002] With the development of modern military technology, the way of fighting has become more diverse, and the demand for protective equipment has also become more diverse. For the production of special-shaped bulletproof products, the most common technology is to use a combined mold consisting of a female mold and a male mold, usually a male-female mold, to lay a certain material on the male mold (or female mold), and then use a press to close the female mold and the male mold and give a certain pressure and temperature for pressing.

[0003] This preparation method of using a press to heat-press the male and female molds has the following problems:

[0004] The use of press equipment and high-pressure molding process cannot achieve single-furnace batch production for special-shaped shells, and the efficiency is low. The use of autoclave equipment and low-pressure molding method can achieve single-furnace batch production with high efficiency.

[0005] For special-shaped shell products with multiple profiles, Figure 1 Taking the bulletproof shell product with multiple profiles as an example, when the press machine is closing the mold and applying pressure, the profiles parallel to the pressing direction of the mold (e.g. Figure 1 There is no pressure on the surface indicated by a), which leads to defects such as poor compaction and delamination on this surface of the product, limiting the protective performance of the product;

[0006] The use of male and female molds can only press bulletproof shells of specified thickness. If the product thickness needs to be increased or reduced, at least the female mold or the male mold needs to be replaced. That is, this method cannot meet the needs of different thicknesses with one set of molds, which increases the cost of mold manufacturing and use. Summary of the invention

[0007] In view of the problems existing in the prior art, the present invention provides the following technical solutions:

[0008] A method for preparing a multi-faceted bulletproof shell, characterized in that it comprises:

[0009] S1. Preparation of flat plate: Lay a certain amount of composite material cloth flat and stack it to form a composite flat plate, add release film on the upper and lower surfaces of the composite flat plate, and then press it into a flat plate on a flat plate press; the prepared flat plate product can be subjected to sufficiently large pressure to ensure that the internal compaction of the product is free of stratification defects and can meet the requirements of protective performance.

[0010] S2. Draw a cutting diagram according to the shapes of different profiles of the multi-profile bullet-proof shell, cut the flat plate obtained in step 1 to obtain corresponding profile blocks, each profile block corresponds to a profile of the multi-profile bullet-proof shell; and then use the remaining part of the flat plate to cut and produce a plurality of long strips of material; so as to facilitate the splicing and combination in subsequent steps.

[0011] S3, wiping the release agent on the surface of the male mold;

[0012] S4. First, lay a certain number of layers of composite material cloth on the male mold in sequence to form a base layer. After laying, cut the corners according to the shape, and lay the whole layer to ensure the integrity of the product;

[0013] S5, placing each profile block on a corresponding profile position, bonding the profile block to the base layer, and fixing each profile block to the corresponding profile position;

[0014] S6, applying a shaping agent to a long strip of material of the same material as the mold surface blocks and placing it in the gap between two adjacent mold surface blocks, and filling the gap with the long strip of material;

[0015] S7. Lay a certain number of layers of one or more of PEUD cloth, aramid woven cloth, and carbon fiber cloth on each of the spliced ​​surface blocks to ensure the integrity of the product;

[0016] S8, vacuum bag wrapping, vacuuming, and putting into autoclave for curing.

[0017] Furthermore, the composite material cloth is one or more of PEUD cloth, aramid woven cloth, carbon fiber cloth, and glass fiber fabric.

[0018] Furthermore, the pressing conditions of the flat plate in S1 include: in the first stage, the pressure is increased to 5±0.1MPa, and the material temperature is increased to 90±2°C; in the second stage, the material temperature is increased to 100±2°C and the pressure is increased to 10±0.1MPa; in the third stage: the material temperature is increased to 132±2°C, the pressure is increased to 25±0.1MPa, then the temperature is kept at 40±5min, and the temperature is reduced to below 30±2°C before demolding.

[0019] Further, in S3, the surface of the male mold is wiped with the release agent three times in total, with the time interval between each wipe being greater than 15 minutes.

[0020] Furthermore, the width of the long strips cut in S2 is 2 mm.

[0021] Furthermore, in S5, the adhesive used to bond the molded surface blocks to the base layer is a thermoplastic resin, a thermosetting resin or a structural adhesive.

[0022] Furthermore, the curing system in S8 is as follows: in the first stage, the pressure is increased to 2±0.1MPa, and the material temperature is increased to 90±2°C; in the second stage, the material temperature is increased to 100±2°C, and the pressure is increased to 3±0.1MPa; in the third stage: the material temperature is increased to 132±2°C, and the pressure is increased to 4±0.1MPa, then the material is kept at this temperature and pressure for 40±5min, and then the material is cooled to below 30±2°C and demolded.

[0023] The present invention only needs one side of the mold (male mold), and the mold cost is low; the prepared flat plate is cut to obtain profile blocks and long strips, and then they are spliced ​​and combined on a single male mold, so that each profile of the special-shaped bullet-proof shell has the same thickness and bulletproof performance; and one male mold can be used to form special-shaped shells of various thicknesses as required, and a single-furnace batch production can be achieved by using autoclave equipment and a low-pressure molding method, with high efficiency, high molded product quality, and good protective performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings that constitute a part of the present invention are used to provide further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 It is a schematic diagram of a bullet-proof shell product having multiple profiles;

[0026] Figure 2 Schematic diagram of the male mold used in the present invention; 1 is the male mold, 2 is the mold base;

[0027] Figure 3 The following is a comparison table of the ballistic performance tests of the comparative examples and the embodiments. DETAILED DESCRIPTION

[0028] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0029] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0030] The present invention only requires one Figure 2 The positive mold shown is sufficient, and no matching negative mold is required, which can reduce the mold design, manufacturing and use costs by half.

[0031] Embodiment 1 using the method of the present invention:

[0032] S1. Prepare a flat plate: cut 120 pieces of PEUD cloth with a size of 990*1100㎜, apply release film on the upper and lower sides, and then press them on a flat plate press. The pressing conditions are as follows: in the first stage, the pressure is increased to 5±0.1MPa, and the material temperature is raised to 90±2℃; in the second stage, the material temperature is increased to 100±2℃, and the pressure is increased to 10±0.1MPa; in the third stage, the material temperature is increased to 132±2℃, and the pressure is increased to 25±0.1MPa, and then the temperature is kept at 40±5min, and the temperature is lowered to below 30±2℃, and the mold is removed;

[0033] S2. According to the different profiles of the special-shaped bullet-proof shell, the product profiles are extracted and the cutting diagram is drawn. The flat plate produced in step 1 is cut to obtain profile blocks corresponding to the shapes of the product profiles, each profile block corresponding to a profile of the product; and the remaining part of the flat plate is used to cut and produce long strips of material with a width of 2 mm;

[0034] S3. Wipe the surface of the male mold 1 with a release agent for a total of 3 times, with each time interval being >15min;

[0035] S4. First, a layer of aramid woven fabric and 8 layers of PEUD fabric are laid on the male mold 1 to form a base layer, and after laying, the cut is made at the special-shaped corners;

[0036] S5. Place the cut surface blocks in step 2 on the corresponding surface, and bond the surface blocks to the PEUD cloth laid in S 4 using a polyurethane adhesive;

[0037] S6. After applying the shaping agent to the long strip, place it in the gap between two adjacent surface blocks and fill the gap with the long strip;

[0038] S7. Lay 9 layers of PEUD cloth on the spliced ​​surface blocks, and finally lay a layer of aramid woven cloth;

[0039] S8. The mold is vacuum-wrapped and evacuated, and then put into the autoclave for curing. The curing system is as follows: in the first stage, the material is pressurized to 2±0.1MPa and the material temperature is raised to 90±2℃; in the second stage, the material temperature is raised to 100±2℃ and the pressure is increased to 3±0.1MPa; in the third stage, the material temperature is raised to 132±2℃ and the pressure is increased to 4±0.1MPa, then the temperature is kept at 40±5min, and the temperature is lowered to below 30±2℃ before demoulding and taking out the mold to obtain a multi-surface bullet-proof shell product.

[0040] Comparative example of preparation using male and female molds for hot pressing:

[0041] 1. Wipe the release agent on the upper and lower surfaces of the combined mold for 3 times, with the time interval between each time greater than 15 minutes;

[0042] 2. Cut 137 pieces of PEUD fabric, the size is 990*1100mm; cut 2 pieces of aramid woven fabric, the size is 990*1100mm;

[0043] 3. Lay a layer of aramid woven fabric on the positive mold, then lay 137 layers of PEUD fabric in sequence, and finally lay a layer of aramid woven fabric. During the laying process, cut the edges at the special-shaped corners.

[0044] 4. Close the upper and lower male and female molds for pressing. The operation steps are as follows: in the first stage, the pressure is increased to 5±0.1MPa, and the material temperature is raised to 90±2℃; in the second stage, the material temperature is raised to 100±2℃, and the pressure is increased to 10±0.1MPa; in the third stage, the material temperature is raised to 132±2℃, and the pressure is increased to 25±0.1MPa, and then the temperature is maintained for 40±5min, and the temperature is lowered to below 30±2℃, and the product is demoulded and taken out.

[0045] Comparative test of products prepared by two methods:

[0046] Within the same surface density range, all the profiles of the special-shaped bulletproof shells prepared in the two embodiments were subjected to target shooting tests. The test conditions were a normal angle of 0° and a 53-type 7.62mm ordinary steel core bullet at a shooting distance of 100m. The target shooting results of the two shell products are as follows: Figure 3 As shown, within the same structure and the same surface density range, the shell facades of the comparative example are all penetrated, and the remaining surfaces can only resist one bullet, and the protection performance is poor. This further illustrates that the product facade is not compacted, the mold cavity is difficult to control, it is difficult to ensure the quality of the product, there is internal stratification, and the ability to resist bullets is poor. The shooting results in Example 2 show that the protection effect of each surface of the product is significantly improved after the new method is adopted, and a certain protection capacity is achieved under the same conditions.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a multi-surface bulletproof shell, characterized in that: include S1. Prepare a flat plate: lay a certain amount of composite material cloth flat and stack it to form a composite flat plate, add release films on the upper and lower surfaces of the composite flat plate, and then put it on a flat plate press to press it into a flat plate; S2, preparing profile blocks and long strips: drawing a cutting diagram according to the shapes of different profiles of the multi-profile bullet-proof shell, cutting the flat plate obtained in S1 to obtain corresponding profile blocks, each profile block corresponding to a profile of the multi-profile bullet-proof shell; and then using the remaining part of the flat plate to cut and produce a plurality of long strips; S3, wiping the release agent on the surface of the male mold; S4. First, lay a certain number of layers of composite material cloth on the male mold in sequence to form a base layer. After laying, cut the corners according to the shape, and lay the whole layer to ensure the integrity of the product; S5, placing each profile block on a corresponding profile position, bonding the profile block to the base layer, and fixing each profile block to the corresponding profile position; S6, applying a shaping agent to a long strip of material of the same material as the mold surface blocks and placing it in the gap between two adjacent mold surface blocks, and filling the gap with the long strip of material; S7. Lay a certain number of layers of one or more of PEUD cloth, aramid woven cloth, and carbon fiber cloth on each of the spliced ​​surface blocks to ensure the integrity of the product; S8, vacuum bag wrapping, vacuuming, and putting into autoclave for curing.

2. The method for preparing a multi-surface bulletproof shell according to claim 1, characterized in that: The composite material cloth is one or more of PEUD cloth, aramid woven cloth, carbon fiber cloth, and glass fiber fabric.

3. The method for preparing a multi-surface bullet-proof shell according to claim 1, characterized in that: The pressing conditions of the flat plate in S1 include: in the first stage, the pressure is increased to 5±0.1MPa, and the material temperature is increased to 90±2℃; in the second stage, the material temperature is increased to 100±2℃, and the pressure is increased to 10±0.1MPa; in the third stage: the material temperature is increased to 132±2℃, and the pressure is increased to 25±0.1MPa, then the temperature is kept at 40±5min, and the temperature is lowered to below 30±2℃ for demolding.

4. The method for preparing a multi-surface bullet-proof shell according to claim 1, characterized in that: In S3, the release agent is wiped on the surface of the male mold three times, and the time interval between each wipe is greater than 15 minutes.

5. The method for preparing a multi-surface bullet-proof shell according to claim 1, characterized in that: The width of the long strips cut in S2 is 2 mm.

6. The method for preparing a multi-surface bullet-proof shell according to claim 1, characterized in that: S5 The adhesive used to bond the profile blocks to the base layer is a thermoplastic resin, a thermosetting resin or a structural adhesive.

7. The method for preparing a multi-surface bullet-proof shell according to claim 1, characterized in that: The curing system in S8 is as follows: in the first stage, the material is pressurized to 2±0.1MPa and the material temperature is raised to 90±2℃; in the second stage, the material temperature is raised to 100±2℃ and the pressure is increased to 3±0.1MPa; in the third stage, the material temperature is raised to 132±2℃ and the pressure is increased to 4±0.1MPa, then the material is kept at this temperature and pressure for 40±5min, and then the material is cooled to below 30±2℃ and demolded.

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